//chinh sua thu
#include"conio.h"
#include"stdio.h"
#include"stdlib.h"
int ktNguyenTo(int a);
int main()
{
   clrscr();
   int N;
   printf("Nhap so tu nhien N=");
   scanf("%d",&N);
   if(ktNguyenTo(N)) printf("N=%d la so nguyen to",N);
   else  printf("N=%d khong phai la so nguyen to",N);
   getch();
   return 0;
}
int ktNguyenTo(int a)
{
   int i;
   for(i=2;i<a;i++)
   if(a%i==0) return 0;
   return 1;
}

